vmware + dual core = sssssssssssssssssssssssslllllllllllllooooowwwww
Today, I ran across the most bizarre problem with vmware. I've got it installed, and configured to emulate (or use, I can't quite tell which) 2 CPUs, on a fairly beefy workstation (2xdual core Opterons) running RHEL5-x86_64. I installed Fedora 7 as the guest OS, however performance was horrific. As in, takes 2 hours to boot up horrific. As in takes an hour to shutdown horrific. At first I thought that this might be some perverse (Fedora 7) tickless kernel bug, but even with it disabled (booting with nohz=off), it was super bad. Finally I thought, I wonder what happens if I fall back to using only a single CPU in vmware, instead of two? It was night & day different. Performance was back to normal (for vmware at least). So clearly there is some really bad bug somewhere. I'm not sure if its vmware, the tickless kernel, or Fedora's tickless kernel, but somewhere something evil is lurking that makes time stand still.